Multi-photo combined adjustment with airborne SAR images based on a few ground control points

This paper introduces an ortho-rectification method of airborne SAR images which is multi-photo combined adjustment method in the circumstances of a few Ground Control Points (GCPs). Multi-photo combined adjustment model and adjustment conditions are given, and the number and distribution of GCPs, pass points is analyzed in this paper. Two adjustment experiments have been done with one-meter resolution airborne SAR images in Chengdu study site. In the two experiments, the GCPs and the Pass Points are distributed rationally in each image. The two experimental results show that the coordinate accuracy of Pass Points is feasible for 1:10 000 scale ortho-image making and topographic map updating. Compared with traditional ortho-rectification, which needs more than six GCPs in single image, this method reduces ground control work dramatically.